Nairobi, Kenya — The death in a helicopter crash of one of Kenya’s longest-serving senior ministers has thrown both the country’s internal fight against Somali extremists and its race for its next president into confusion.

George Saitoti, Kenya’s internal security minister and its former vice-president and finance minister, was killed yesterday when his police helicopter came down in a forested area in hills southeast of Nairobi, the capital. The crash also killed his ministerial deputy, Joshua Ojode, two bodyguards, and the two pilots.

Kenya’s president, Mwai Kibaki, has declared three days of official mourning, and a full investigation into the crash is planned.

Mr. Saitoti’s job put him in charge of preventing Somalia’s Al Shabab terror group from carrying out its threats to attack targets inside Kenya. He was also a key hawk in Mr. Kibaki’s government who pushed for aggressive action against Al Shabab inside Somalia following a series of kidnappings of Westerners in Kenya last year.

Saitoti’s successor at the internal security ministry has not yet been named, but whoever takes the job is unlikely to take a softer line in the war against the Islamists. Given Saitoti's hawkish views, suspicions quickly surfaced that the crash may not have been an accident.

A government spokesman said that there were no suggestions of foul play, but Kenya’s prime minister, Raila Odinga, said that “as we speak now, nobody knows the cause of the accident.”

Al Shabab, which would be expected to claim responsibility quickly if it were behind the crash, said on its Twitter page only that it “welcomed” the death of the minister “upon whose authorization thousands of Muslims have suffered both in Kenya and Somalia.”

Following last year's kidnappings, Kenya invaded Somalia and succeeded in squeezing Al Shabab from key strongholds. Kenyan troops have folded into the African Union Mission in Somalia (AMISOM), which has seen a series of successes against Al Shabab in recent months.

The shock of Saitoti’s death has pulsed through Kenyan society, and has raised questions about maintenance of state aircraft. The helicopter involved was a Eurocopter AS350 B3e, which was built in 2011 and was delivered to Kenyan police in December.

His death was not the first in a police or military aircraft. Two ministers died in a small Cessna southeast of Nairobi four years ago, and in January 2003, just weeks after Mr. Kibaki's government came to power, another light aircraft carrying government ministers crashed in western Kenya killing one minister and three others. Three other ministers survived the accident.

Saitoti was expected to contest Kenya’s presidential election in March next year, one of 20 men and women who have already thrown their hats in the ring.

He was born to a poor family in Masailand south of Nairobi, but went on to education in Britain and Brandeis University outside Boston, and rose to become one of his generation’s most respected academic mathematicians.

He was finance minister under the former president, Daniel arap Moi, and served as vice-president on several occasions between 1988 and 2002. President Kibaki said the deaths were "a devastating loss to our country.”

"Minister Saitoti will forever be remembered as a hardworking and determined public servant who dedicated his time to the service of the Kenyan people," he said Sunday.

Editor's note: The original story misstated the location of a 2005 helicopter crash.